ELECSYS CMV IGM

Additional Manufacturer Narrative

THE ANALYZER SERIAL NUMBER IS (B)(6). THE CALIBRATION AND QC RECOVERY DATA PROVIDED WAS WITHIN SPECIFICATION. PER PRODUCT LABELING, "A NEGATIVE CMV IGM TEST RESULT, ALSO IN COMBINATION WITH A POSITIVE CMV IGG RESULT, DOES NOT COMPLETELY RULE OUT THE POSSIBILITY OF AN ACUTE INFECTION WITH CMV. INDIVIDUALS AT THE EARLY STAGE OF ACUTE INFECTION MAY NOT EXHIBIT DETECTABLE AMOUNTS OF CMV IGM ANTIBODIES. IN SOME OF THESE INDIVIDUALS AN BORDERLINE OR LOW POSITIVE RESULT WITH THE ELECSYS CMV IGG ASSAY MAY BE FOUND AND INDICATE AN EARLY ACUTE INFECTION. A SECOND SAMPLE SHOULD BE TESTED E.G. WITHIN 2-3 WEEKS. THE DETECTION OF CMV IGM AND/OR A SIGNIFICANT INCREASE OF THE ELECSYS CMV IGG ANTIBODY TITER IN THE SECOND SAMPLE SUPPORTS THE DIAGNOSIS OF ACUTE CMV INFECTION. THE INDIVIDUAL IMMUNE RESPONSE FOLLOWING CMV INFECTION VARIES CONSIDERABLY. IN SOME INDIVIDUALS NON-REACTIVE RESULTS MAY OCCUR IN THE LATE PHASE OF ACUTE INFECTION WITH THE ELECSYS CMV IGM ASSAY." THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.

Description of Event or Problem

THERE WAS AN ALLEGATION OF A QUESTIONABLE ELECSYS CMV IGM RESULT FOR 1 PATIENT SAMPLE ON A COBAS E 801 ANALYTICAL UNIT COMPARED TO A DIASORIN ANALYZER. THIS MDR IS BEING SUBMITTED IN AN ABUNDANCE OF CAUTION. ON (B)(6) 2025, THE CMV IGM RESULT WAS 0.48 IU/ML (NEGATIVE) AND THE CMV IGG RESULT WAS 3.91 IU/ML (POSITIVE). THE PATIENT WAS 9 WEEKS AND 2 DAYS PREGNANT, AND THE RESULTS INDICATED CMV IMMUNITY. WHEN THE PATIENT WAS 22 WEEKS PREGNANT, SEVERE FETAL BRAIN ABNORMALITIES WERE DETECTED SUGGESTING FETAL CYTOMEGALOVIRUS INFECTION. AMNIOCENTESIS WAS PERFORMED AND CMV PCR IN AMNIOTIC FLUID GAVE A POSITIVE RESULT, CONFIRMING FETAL CMV INFECTION. THE SEVERITY OF THE BRAIN LESIONS WAS CONFIRMED BY MRI OF THE FETAL BRAIN AND TERMINATION OF PREGNANCY WAS PERFORMED. THE PATIENT SAMPLE FROM (B)(6) 2025 WAS RETESTED ON A DIASORIN ANALYZER AND THE CMV IGM RESULT WAS 51.7 IU/ML (POSITIVE) AND THE CMV IGG RESULT WAS <5 IU/ML (NEGATIVE). THE EXACT DATE OF TESTING WAS NOT PROVIDED. ON (B)(6) 2026, THE SAMPLE FROM (B)(6) 2025 WAS REPEATED ON LINE 1 OF THE COBAS ANALYZER AND THE CMV IGM RESULT WAS 0.51 (NEGATIVE) IU/ML AND THE CMV IGG RESULT WAS 3.43 IU/ML (POSITIVE). THE SAMPLE WAS REPEATED AGAIN ON LINE 2 AND THE IGM RESULT WAS 0.54 IU/ML (NEGATIVE) AND THE IGG RESULT WAS 3.12 IU/ML (POSITIVE).